Workpiece holder for a workbench



FIG. 1 is an end view of a workpiece holder for a workbench showing my new design with the opposite end being a mirror image thereof;

FIG. 2 is a side view of the workpiece holder for a workbench with the opposite side being a mirror image;

FIG. 3 is a bottom view of the workpiece holder for a workbench of FIG. 1; and,

FIG. 4 is a top view of the workpiece holder for a workbench of FIG. 1 of my new design. 

The ornamental design for a workpiece holder for a workbench, as shown and described. 